Stem Investigation

What are the parts of a stem and why are these parts important for plant growth and survival? Make observations about the parts and features of stems and make inferences about how stems help plants grow and survive.

Materials

• Mixture of plants with soft, hard, and/or edible stems

• The cross-section of a log (optional)

• Magnifying glass (optional)

• Paper and writing utensil (optional)

• Crayons (optional)

• Access to a garden (or similar space) (optional)

Observation Ideas

• With the naked eye, look closely at the stem of a soft (herbaceous) plant (basil, mint, cilantro); the stem of a hard (woody) plant like a tree, shrub, or some vines (Japanese honeysuckle, grapevines); and/or a plant with an edible stem (asparagus, cauliflower, broccoli).

• Use a magnifying glass to look closely at the textures on the stems. Are the stems smooth, bumpy, thorny, spiky?

Discussion Ideas

• Stems connect the roots to the leaves and flowers and function as transport routes for water, nutrients, and food. Draw a picture of a plant taking in water and nutrients from the roots and transporting them to the other parts of the plant.

• Feel and compare soft and hard stems. What might be some advantages and disadvantages of each structure?

• Look closely at the texture of tree bark by creating a tree bark rubbing. How would a tree benefit from having thick bark?

• Inspect the cross-section of a log to view the inside of a stem. What parts do you notice?

Further Investigation Ideas

• Use a magnifying glass to examine the buds at the nodes of the plant where new stems or flowers are growing. Predict if the bud will grow into a stem or flower and explain why you think that.

• Use a protractor to measure the angles of different branches from the stem on the same plant. What is the range of angles? Did you notice any patterns where you found bigger or smaller angles?